Configuration for the EhCache TicketRegistry which stores the tickets in a distributed EhCache and cleans them out as specified intervals. Service Tickets (ST) and Proxy Tickets are only valid for short amount of time (default is 10 seconds), and most often are removed from the cache when the ST is validated. The ST cache must be replicated quickly since validation is expected within a few second after its creation. The CAS instance validating the ST may not be one that created the ST, since validation is a back-channel service-to-CAS call that is not aware of user session affinity. Synchronous mode is used to ensure all CAS nodes can validate the ST. Ticket Granting Tickets (TGT) are valid for the lifetime of the SSO Session. They become invalid either by expiration policy (default 2 hours idle, 8 hours max) or by explicit user sign off via /cas/login. The TGT cache can be replicated slowly because TGT are only manipulated via web user started operations (mostly grant service ticket) and thus benefit of web session affinity.